Mouse L-cells Research Articles

Lysine grafted poly(lactic acid): An intrinsically antimicrobial polymer

Nosocomial infections or healthcare-associated infections, normally develops after the healthcare treatment in the hospital. Most of them are caused by infected medical devices. Plastics are the most common materials for manufacturing these devices because of their good processability, sterilization efficacy, ease of handling and harmlessness, however, it usually do not display antimicrobial properties. Here, in order to infer antimicrobial activity to poly(lactic acid), it was modified by maleation, followed by l-lysine grafting to its structure. The chemical modifications were confirmed by FTIR and 1H NMR analysis, indicating the success of the reactions. The antimicrobial activity was tested using Escherichia coli and Staphylococcus aureus and the results showed that the sample was capable of inhibiting about 99 % of the S. aureus growth by contact. The samples cytotoxicity was also tested using the L929 mouse cells and the results indicated no cytotoxic effect. These results indicated the sample antimicrobial potential, without affect the normal eukaryotic cells. In addition, the processability of the modified PLA (PLA-g-Lys) was improved without compromising its mechanical properties, as shown by thermal analysis and tensile tests. Thus, this novel PLA derivative can be seen as a promising material for future applications in the manufacturing of biomedical devices.

Antimicrobial assay and controlled drug release studies with novel eugenol imprinted p(HEMA)-bacterial cellulose nanocomposite, designed for biomedical applications

In this study, a novel bio-composite material that allow sustained release of plant derived antimicrobial compound was developed for the biomedical applications to prevent the infections caused by microorganisms resistant to commercial antimicrobials agents. With this aim, bacterial cellulose (BC)-p(HEMA) nanocomposite film that imprinted with eugenol (EU) via metal chelated monomer, MAH was prepared. Firstly, characterization studies were utilized by FTIR, SEM and BET analysis. Then antimicrobial assays, drug release studies and in vitro cytotoxicity test were performed. A significant antimicrobial effect against both Gram (+) Staphylococcus aureus and Gram (-) Escherichia coli bacteria and a yeast Candida albicans were observed even in low exposure time periods. When antimicrobial effect of EU compared with commercially used agents, both antifungal and antibacterial activity of EU were found to be higher. Then, sustained drug release studies showed that approximately 55% of EU was released up to 50 h. This result proved the achievement of the molecular imprinting for an immobilization of molecules that desired to release on an area in a long-time interval. Finally, the in vitro cytotoxicity experiment performed with the mouse L929 cell line determined that the synthesized EU-imprinted BC nanocomposite was biocompatible.

Enhanced Antimicrobial Activity of Laser‐induced Graphene Wrapped Tri‐Metal Organic Framework Nanocomposites

Crystalline and porous metal‐organic frameworks (MOFs) are potential candidates for different antibacterial, photocatalytic, and adsorption applications. Moreover, multi‐principal element nanoparticles are effective against multidrug‐resistant bacteria, and combining metals with carbon nanomaterials can enhance activity. In this study, a Tri‐MOF comprised of iron, zinc, and cobalt and 2‐methyl imidazole was grown together with laser‐induced graphene (LIG) powder. Electron microscopy imaging showed the successful preparation and the crystalline nature of the LIG/Tri‐MOF composite. Fourier‐transform infrared and X‐ray photoelectron spectroscopy confirmed a non‐covalent mixture of LIG and Tri‐MOF. Compared with the negligible activity of LIG alone, low doses (0.91‐4.54 mg/mL) of the prepared LIG/Tri‐MOF composite showed excellent antibacterial activity (≥ 95% bacterial removal) and a MIC of 0.6 mg/mL, for Gram‐negative bacteria via the gradual leaching of metal ions and organic linker from the material enhanced by bacterial aggregation near the LIG/Tri‐MOF. Compared to a mixture of separately synthesized Tri‐MOF and LIG, the LIG/Tri‐MOF composite showed improved antibacterial effects. All materials showed cytotoxicity for L929 mouse cell lines, the solids showing a disrupting effect on cells grown in vitro. Performance‐enhancing combinations of various materials leading to synergistic or additive antimicrobial effects is an essential strategy for minimizing the possible emergence of antibiotic‐resistant strains.This article is protected by copyright. All rights reserved.

Common food additive carrageenan inhibits proglucagon expression and GLP-1 secretion by human enteroendocrine L-cells

Proglucagon mRNA expression and GLP-1 secretion by cultured human L-cells (NCI-H716) were inhibited following exposure to λ-carrageenan, a commonly used additive in processed foods. Carrageenan is composed of sulfated or unsulfated galactose residues linked in alternating alpha-1,3 and beta-1,4 bonds and resembles the endogenous sulfated glycosaminoglycans. However, carrageenan has unusual alpha-1,3-galactosidic bonds, which are not innate to human cells and are implicated in immune responses. Exposure to carrageenan predictably causes inflammation, and carrageenan impairs glucose tolerance and contributes to insulin resistance. When cultured human L-cells were deprived overnight of glucose and serum and then exposed to high glucose, 10% FBS, and λ-carrageenan (1 µg/ml) for 10 minutes, 1 h, and 24 h, mRNA expression of proglucagon and secretion of GLP-1 were significantly reduced, compared to control cells not exposed to carrageenan. mRNA expression of proglucagon by mouse L-cells (STC-1) was also significantly reduced and supports the findings in the human cells. Exposure of co-cultured human intestinal epithelial cells (LS174T) to the spent media of the carrageenan-treated L-cells led to a decline in mRNA expression of GLUT-2 at 24 h. These findings suggest that ingestion of carrageenan-containing processed foods may impair the production of GLP-1, counteract the effect of GLP-1 receptor agonists and induce secondary effects on intestinal epithelial cells.

Sprayable hydroxypropyl chitin/collagen extract of Ampelopsis brevipedunculata hydrogel accelerates wound healing.

Keeping a wound moist can allow effective and rapid healing, and it can control the formation of scabs, thereby allowing cell proliferation and epithelial formation. When regularly changing a dressing, thermosensitive hydrogel as a moist dressing does not cause a secondary wound from adhesion. The main aim of this study was to evaluate the effect of a new sprayable thermosensitive hydrogel on wound healing. The hydrophobic N-acetyl group of chitin was removed by microwave reaction with lye until the degree of acetylation was 60%, followed by reaction with propylene oxide to obtain hydroxypropyl chitin (HPCH) with a degree of substitution of 40%. After mixing HPCH with fish scale collagen (FSC), a thermosensitive hydrogel with a gel temperature of 26.5°C was obtained. Ampelopsis brevipedunculata extracts (ABE), which have been found to accelerate wound repair and improve healing, were added. HPCH/FSC is not toxic to the mouse L929 cell line and forms a hydrogel at body surface temperature. It can be easily sprayed on a wound. The HPCH/FSC has a three-dimensional network porous structure with a swelling ratio of 10.95:1 and a water vapour transmission rate of 2386.03±228.87g/m2/day; it can facilitate the penetration of water and air, and promote absorption of wound exudate. Wound repair was performed on five Sprague-Dawley rats. Each rat had three wounds, which were treated with medical gauze, HPCH/FSC and HPCH/FSC/ABE, respectively. The wounds in the HPCH/FSC/ABE group recovered the fastest in vivo, the mature wound site was smoother, the re-epithelialisation was even and thicker, and the angiogenesis developed rapidly to the mature stage. In this study, HPCH/FSC/ABE thermosensitive hydrogel was shown to effectively accelerate wound healing and was convenient for practical application.

The role of the HERG channel in the secretion of glucagon-like peptide-1 (GLP-1) from murine intestinal L-cells

The HERG ion channel belongs to the voltage-gated potassium (Kv) channel family and is involved in potassium efflux during cellular repolarization. Mutations in HERG have been linked to long QT syndrome, which is associated with elevated secretion of glucagon-like peptide-1 (GLP-1). However, the precise contribution of HERG to GLP-1 secretion remains unclear. In this study, we demonstrate the expression of HERG in GLP-1-producing L-cells within the intestinal epithelium of rodents. Using a mouse L-cell model (GLUTag cell line), we observed that downregulation of HERG led to a significant prolongation of action potential duration, an increase in intracellular calcium concentration, and a stimulation of GLP-1 secretion following exposure to nutrients. These findings provide evidence that HERG plays a direct role in regulating GLP-1 secretion in the intestine and may hold promise as a potential target for the treatment of diabetes.

Biological Activity and Thrombogenic Properties of Oxide Nanotubes on the Ti-13Nb-13Zr Biomedical Alloy.

The success of implant treatment is dependent on the osseointegration of the implant. The main goal of this work was to improve the biofunctionality of the Ti-13Nb-13Zr implant alloy by the production of oxide nanotubes (ONTs) layers for better anchoring in the bone and use as an intelligent carrier in drug delivery systems. Anodization of the Ti-13Nb-13Zr alloy was carried out in 0.5% HF, 1 M (NH4)2SO4 + 2% NH4F, and 1 M ethylene glycol + 4 wt.% NH4F electrolytes. Physicochemical characteristics of ONTs were performed by high-resolution electron microscopy (HREM), X-ray photoelectron spectroscopy (XPS), and scanning Kelvin probe (SKP). Water contact angle studies were conducted using the sitting airdrop method. In vitro biological properties and release kinetics of ibuprofen were investigated. The results of TEM and XPS studies confirmed the formation of the single-walled ONTs of three generations on the bi-phase (α + β) Ti-13Nb-13Zr alloy. The ONTs were composed of oxides of the alloying elements. The proposed surface modification method ensured good hemolytic properties, no cytotoxity for L-929 mouse cells, good adhesion, increased surface wettability, and improved athrombogenic properties of the Ti-13Nb-13Zr alloy. Nanotubular surfaces allowed ibuprofen to be released from the polymer matrix according to the Gallagher-Corrigan model.

Unidirectional Nanopore Dehydration Induces a Highly Stretchable and Mechanically Robust Silk Fibroin Membrane Dominated by Type II β-Turns.

Aqueous silk fibroin solution is dehydrated by evaporation into a water-soluble cast film (SFME) with poor mechanical properties but becomes by unidirectional nanopore dehydration (UND) into silk fibroin membrane (SFMU) with water-stable and good mechanical robustness. The thickness and tensile force of the SFMU are almost twice those of the MeOH-annealed SFME. The UND-based SFMU has a tensile strength of 15.82 MPa, an elongation of 665.23%, and a type II β-turn (Silk I) that accounts for 30.75% of the crystal structure. Mouse L-929 cells adhere, grow, and proliferate well on it. The UND temperature can be used to tune the secondary structure, mechanical properties, and biodegradability. UND induced the oriented arrangement of the silk molecules, which led to the formation of the SFMU dominated with Silk I structure. The silk metamaterial by controllable UND technology has great potential in medical biomaterials, biomimetic materials, sustained drug release, and flexible electronic substrates.

Mammalian Reoviruses: Propagation, Quantification, and Storage.

Mammalian reoviruses are pathogens that cause gastrointestinal and respiratory infections. In humans, the mammalian reoviruses usually cause mild or subclinical disease, and they are ubiquitous, with most people mounting immunity at a young age. Reoviruses are prototypic representations of the Reoviridae family, which contains many highly pathogenic viruses. This article describes techniques for culturing mouse fibroblast L929 cell lines, the preferred cell line in which most mammalian reovirus studies take place. In addition, mammalian reovirus propagation, quantification, purification, and storage are described. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Propagation of mammalian reoviruses in cell culture from virus stocks Alternate Protocol 1: Large-scale propagation (and purification) of mammalian reoviruses in cell culture from virus stocks Basic Protocol 2: Quantification of mammalian reoviruses by plaque assay with neutral red staining Alternate Protocol 2: Quantification of mammalian reoviruses by plaque assay with crystal violet staining Basic Protocol 3: Storage of mammalian reoviruses Support Protocol 1: Growth and maintenance of mouse L929 cells Support Protocol 2: Plating L929 cells.

Isolation, phytochemical elucidation, and wound healing potential of chitosan-based film loaded with Tagetes erecta

The research aims to study the wound healing potential of Tagetes erecta flower extract. The flowers were subjected to solvent extraction and the extracts were further subjected to initial phytochemical analysis which led to the selection of ethyl acetate (EA) extract. GCMS analysis of EA extract showed the presence of siloxane derivatives, sugars, and acidic compounds such as phenolic and ascorbic acid derivatives some of which are responsible for wound healing activity. The presence of BHT having highest peak made it clear that the extract can contribute to wound healing process by antioxidant activity. MTT assay of EA extract using mouse L929 cell lines revealed that all experimental concentrations were found to be non-toxic in nature. Further, three film formulations (M1, M2, M3) were developed by varying the amount of EA extract loaded in chitosan and evaluated based on parameters like hydrolytic degradation, water vapour transmission rate, folding endurance, percentage moisture content and swelling index. Based on these results, film M2 was found to be better, and its wound healing activity was determined by scratch assay. Results exhibited 61.82% of cell migration in comparison to positive control 40.83% (5% povidone iodine). The presence of antibacterial bioactive components in the EA extract was further confirmed by the anti-bacterial study against gram-positive and gram-negative bacteria. Thus, developed chitosan films loaded with marigold flower extract can be a promising material which can be further evaluated for exhibiting wound healing activity.

Development and in-vitro characterization of HAP blended PVA/PEG bio-membrane

Hydroxyapatite HAP is a bioceramic that can be applied for bone tissue regeneration. Polyvinyl Alcohol (PVA)/Polyethylene Glycol (PEG) polymers are water-soluble and have faster biodegradation properties. The PVA-PEG-HAp thin membrane was cast by using the transparent solution petri-dish method. The PVA-PEG-HAp thin membrane was investigated by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Energy Dispersive X-Ray Analysis (EDX), and Field Emission Scanning Electron Microscope (FESEM. Both PVA and HAp of membrane matrix had typical peaks at 2Ɵ value 19.78. PEG also has a distinctive peak at 26.687. The five (5, 25, 50, 75, and 10 μl) different concentrations of extracts of PVA-PEG-HAp thin membrane were pertinent to interacting for 24 h with the L929 mouse cell line, and the results were exhibited a maximum of 99% and 93% cell viability, 1% and 7% cytotoxicity, respectively. Hence the newly developed polymer biomembrane is a biocompatible alternative for biofilms in medical applications.

Accelerated Discovery of Potent Bioactive anti-TNFα Aptamers by Microbead-Assisted Capillary Electrophoresis (MACE)-SELEX.

Dysregulation of tumor necrosis factor-α (TNFα), a pro-inflammatory cytokine, causes several diseases, making it an important therapeutic target. Here, we identified a novel DNA aptamer against human TNFα using in vitro selection, which included a high exclusion pressure process against non-binding and weak binders through microbead-assisted capillary electrophoresis (MACE) in only three rounds. Among the 15 most enriched aptamers, Apt14 exhibited the highest inhibitory activity for the interaction between TNFα and its cognate receptor in mouse L929 cells. For further improving the bioactivity of the aptamer, dimerization programed by hybridization was evaluated, resulting in the Apt14 dimer exhibited a twofold higher binding affinity and stronger inhibition compared to the monomer counterpart. Rapid identification of bioactive aptamers using MACE in combination with facile dimerization by hybridization accelerates the discovery of novel bioactive aptamers, paving the way toward replacing current monoclonal antibody therapy with the less expensive and non-immunogenic aptamer therapy.

A new cell-sized support for 3D cell cultures based on recombinant spider silk fibers.

It is now generally accepted that 2D cultures cannot accurately replicate the rich environment and complex tissue architecture that exists in vivo, and that classically cultured cells tend to lose their original function. Growth of spheroids as opposed to 2D cultures on plastic has now been hailed as an efficient method to produce quantities of high-quality cells for cancer research, drug discovery, neuroscience, and regenerative medicine. We have developed a new recombinant protein that mimics dragline spidersilk and that self-assembles into cell-sized coils. These have high thermal and shelf-life stability and can be readily sterilized and stored for an extended period of time. The fibers are flexible, elastic, and biocompatible and can serve as cell-sized scaffold for the formation of 3D cell spheroids. As a proof of concept, recombinant spidersilk was integrated as a scaffold in spheroids of three cell types: primary rat hepatocytes, human mesenchymal stem cells, and mouse L929 cells. The scaffolds significantly reduced spheroid shrinkage and unlike scaffold-free spheroids, spheroids did not disintegrate over the course of long-term culture. Cells in recombinant spidersilk spheroids showed increased viability, and the cell lines continued to proliferate for longer than control cultures without spidersilk. The spidersilk also supported biological functions. Recombinant spidersilk primary hepatocyte spheroids exhibited 2.7-fold higher levels of adenosine triphosphate (ATP) continued to express and secrete albumin and exhibited significantly higher basal and induced CYP3A activity for at least 6 weeks in culture, while control spheroids without fibers stopped producing albumin after 27 days and CPY3A activity was barely detectable after 44 days. These results indicate that recombinant spidersilk can serve as a useful tool for long-term cell culture of 3D cell spheroids and specifically that primary hepatocytes can remain active in culture for an extended period of time which could be of great use in toxicology testing.

L-Cell Expression of Melanocortin-4-Receptor Is Marginal in Most of the Small Intestine in Mice and Humans and Direct Stimulation of Small Intestinal Melanocortin-4-Receptors in Mice and Rats Does Not Affect GLP-1 Secretion.

The molecular sensors underlying nutrient-stimulated GLP-1 secretion are currently being investigated. Peripheral administration of melanocortin-4 receptor (MC4R) agonists have been reported to increase GLP-1 plasma concentrations in mice and humans but it is unknown whether this effect results from a direct effect on the GLP-1 secreting L-cells in the intestine, from other effects in the intestine or from extra-intestinal effects. We investigated L-cell expression of MC4R in mouse and human L-cells by reanalyzing publicly available RNA sequencing databases (mouse and human) and by RT-qPCR (mouse), and assessed whether administration of MC4R agonists to a physiologically relevant gut model, isolated perfused mouse and rat small intestine, would stimulate GLP-1 secretion or potentiate glucose-stimulated secretion. L-cell MC4R expression was low in mouse duodenum and hardly detectable in the ileum and MC4R expression was hardly detectable in human L-cells. In isolated perfused mouse and rat intestine, neither intra-luminal nor intra-arterial administration of NDP-alpha-MSH, a potent MC4R agonist, had any effect on GLP-1 secretion (P ≥0.98, n = 5–6) from the upper or lower-half of the small intestine in mice or in the lower half in rats. Furthermore, HS014—an often used MC4R antagonist, which we found to be a partial agonist—did not affect the glucose-induced GLP-1 response in the rat, P = 0.62, n = 6). Studies on transfected COS7-cells confirmed bioactivity of the used compounds and that concentrations employed were well within in the effective range. Our combined data therefore suggest that MC4R-activated GLP-1 secretion in rodents either exclusively occurs in the colon or involves extra-intestinal signaling.

NFAT5 Is Involved in GRP-Enhanced Secretion of GLP-1 by Sodium.

Gastrin, secreted by G-cells, and glucagon-like peptide-1 (GLP-1), secreted by L-cells, may participate in the regulation of sodium balance. We studied the effect of sodium in mice in vivo and mouse ileum and human L-cells, on GLP-1 secretion, and the role of NFAT5 and gastrin-releasing peptide receptor (GRPR) in this process. A high-sodium diet increases serum GLP-1 levels in mice. Increasing sodium concentration stimulates GLP-1 secretion from mouse ileum and L-cells. GRP enhances the high sodium-induced increase in GLP-1 secretion. High sodium increases cellular GLP-1 expression, while low and high sodium concentrations increase NFAT5 and GRPR expression. Silencing NFAT5 in L-cells abrogates the stimulatory effect of GRP on the high sodium-induced GLP-1 secretion and protein expression, and the sodium-induced increase in GRPR expression. GLP-1 and gastrin decrease the expression of Na+-K+/ATPase and increase the phosphorylation of sodium/hydrogen exchanger type 3 (NHE3) in human renal proximal tubule cells (hRPTCs). This study gives a new perspective on the mechanisms of GLP-1 secretion, especially that engendered by ingested sodium, and the ability of GLP-1, with gastrin, to decrease Na+-K+/ATPase expression and NHE3 function in hRPTCs. These results may contribute to the better utilization of current and future GLP-1-based drugs in the treatment of hypertension.

The toxicology properties of modified hydrothermal nanotitania extraction.

IntroductionThe nanoparticle has become a part of world industry. This substance has been proven as potentially beneficial for its usage as a catalyst and semi-conductor due to its high surface area and the effects of the quantum size effect. It exhibits potential characteristics and would be applied in a wider scope of usage compared to bulk particles because the smaller the size of the particles, the more room for the extent of their usage. Nano titanium dioxide application as semi-conductors together with a catalyst is highly attributed to its high photochemical stability and ability to be produced at a low-cost. The consequence of this – exposure of nano titanium dioxide particles to humans – raises concerns regarding health and safety. Therefore, this research action works designed to offer a thorough analysis of toxicology impacts produced by our own synthesis modified hydrothermal in vitro experiments.Material and methodsOur nanotitania extraction with 0.05% silver was tested for its toxicity against L929 mouse cells. The cytotoxicity effect of nanotitania extract was evaluated by MTT assay. Cell viability (% CV) was calculated using a formula.ResultsThere are non-cytotoxicity activity of 0.05% nanotitania at concentrations 1.5, 3.1, 6.3, 12.5, and 25 mg/ml on L929 cell lines except at concentration 50 and 100 mg/ml. The result was related to the optical density reading.ConclusionsThere is no cytotoxic effect of nanotitania extraction with 0.05% silver in the growth inhibition test with L929 mouse with the exception of the 100 mg/ml extract.

Cytotoxic Effect of Saffron Stigma Aqueous Extract on Human Prostate Cancer and Mouse Fibroblast Cell Lines.

Several lines of experimental evidence have shown that saffron has anticarcinogenic effects. This study aimed at evaluating the possible anticancer effect of saffron stigma aqueous extract on human prostate cancer (PC3) and mouse fibroblast cells (L929) as non-cancerous control cells. Saffron stigma aqueous extract at concentrations of 100, 200, 400, 600, 800, 1600 and 3200 μg/mL were prepared. PC3 and L929 cells were incubated with different concentrations of saffron extracts in different time intervals (24, 48, 72, 96 and 144 hours). MTT assay was used for each cell line to investigate the cytotoxic effect of saffron. Morphological alterations were also observed under light inverted microscope. In fibroblast cell line after 24 hours, Saffron extract did not affect significantly the normal cells and they were intact in morphologic view. After 96 hours in the cells with highest concentration (1600 μg/mL), cell death and cellular form changes as well as severe granulation was observed. In prostate cell line after 24 hours, the only changes were observed in cells with the concentration of 1600 μg/mL. The cells were granulated and the form of the cells were spherule. After 72 hours, in group with the concentration of 1600 μg/mL, severe granulation was observed and the cell count decreased and some cells were dead. Saffron aqueous extract has an in vitro inhibitory effect on the proliferation of human prostate cell and mouse L929 cells which is dose-dependent.

The Protective Role of Hydrogen Sulfide Against Obesity-Associated Cellular Stress in Blood Glucose Regulation

Circulating palmitic acid (PA) is increased in obesity and causes metabolic stress, leading to diabetes. This includes the impairment of the glucoregulatory hormone glucagon-like peptide-1 (GLP-1) secreted from intestinal L-cells. Recently, the anti-inflammatory gasotransmitter hydrogen sulfide (H2S) has been implicated in the enhancement of GLP-1 secretion. We hypothesized that H2S can reduce the oxidative stress caused by palmitate and play a protective role in L-cell function. This study was conducted on both human and mouse L-cells and a mouse model of Western diet (WD)-induced obesity. PA-induced L-cell stress was assessed using DCF-DA. H2S was delivered using the donor GYY4137. C57BL/6 mice were fed either chow diet or PA-enriched WD for 20 weeks with ongoing measurements of glycemia and GLP-1 secretion. In both L-cell models, we demonstrated that PA caused an increase in reactive oxygen species (ROS). This ROS induction was partially blocked by the H2S administration. In mice, the WD elevated body weight in both sexes and elevated fasting blood glucose and lipid peroxidation in males. Additionally, a single GYY4137 injection improved oral glucose tolerance in WD-fed male mice and also enhanced glucose-stimulated GLP-1 release. To conclude, H2S reduces oxidative stress in GLP-1 cells and can improve glucose clearance in mice.

The Performance of Cemented Femoral Prosthesis Based on New Gel Materials

In view of the problems in hip replacement, a new gel material is developed and incorporated into cemented femoral prosthesis. The material precipitates hydroxyapatite (HA) onto silk fibroin (SF) by biomimetic method, namely silk fibroin hydroxyapatite (SF–HA). Through X-ray diffraction (XRD) and scanning electron microscope (SEM) analysis, HA precipitates on SF. Taking the gel time as the standard, 5 groups of gel materials are selected. Through in vitro degradation experiments, the degradation rate of these materials is 45%∼55%. Cell experiments (mouse L929 cells, osteoblasts HO-F) show that these cells have no cytotoxicity and support the growth of osteoblasts. In addition, in the vivo experiment (two groups), one group was treated with gelatin materials and the other group is treated with bone cement prosthesis transplantation directly. Comparing the indexes before and after operation, it proves that the new gel material has great application value in hip replacement surgery.

The VSV matrix protein inhibits NF-κB and the interferon response independently in mouse L929 cells

The matrix (M) protein of vesicular stomatitis virus (VSV) plays a key role in immune evasion. While VSV has been thought to suppress the interferon (IFN) response primarily by inhibiting host cell transcription and translation, our recent findings indicate that the M protein also targets NF-κB activation. Therefore, the M protein may utilize two distinct mechanisms to limit expression of antiviral genes, inhibiting both host gene expression and NF-κB activation. Here we characterize a recently reported mutation in the M protein [M(D52G)] of VSV isolate 22–20, which suppressed IFN mRNA and protein production despite activating NF-κB. 22–20 inhibited reporter gene expression from multiple promoters, suggesting that 22-20 suppressed the IFN response via M-mediated inhibition of host cell transcription. We propose that suppression of the IFN response and regulation of NF-κB are independent, genetically separable functions of the VSV M protein.